--- /dev/null
+/*
+ * Broadcom STB CPU SMP and hotplug support for ARM
+ *
+ * Copyright (C) 2013-2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/printk.h>
+#include <linux/regmap.h>
+#include <linux/smp.h>
+#include <linux/mfd/syscon.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/mach-types.h>
+#include <asm/smp_plat.h>
+
+#include "brcmstb.h"
+
+enum {
+ ZONE_MAN_CLKEN_MASK = BIT(0),
+ ZONE_MAN_RESET_CNTL_MASK = BIT(1),
+ ZONE_MAN_MEM_PWR_MASK = BIT(4),
+ ZONE_RESERVED_1_MASK = BIT(5),
+ ZONE_MAN_ISO_CNTL_MASK = BIT(6),
+ ZONE_MANUAL_CONTROL_MASK = BIT(7),
+ ZONE_PWR_DN_REQ_MASK = BIT(9),
+ ZONE_PWR_UP_REQ_MASK = BIT(10),
+ ZONE_BLK_RST_ASSERT_MASK = BIT(12),
+ ZONE_PWR_OFF_STATE_MASK = BIT(25),
+ ZONE_PWR_ON_STATE_MASK = BIT(26),
+ ZONE_DPG_PWR_STATE_MASK = BIT(28),
+ ZONE_MEM_PWR_STATE_MASK = BIT(29),
+ ZONE_RESET_STATE_MASK = BIT(31),
+ CPU0_PWR_ZONE_CTRL_REG = 1,
+ CPU_RESET_CONFIG_REG = 2,
+};
+
+static void __iomem *cpubiuctrl_block;
+static void __iomem *hif_cont_block;
+static u32 cpu0_pwr_zone_ctrl_reg;
+static u32 cpu_rst_cfg_reg;
+static u32 hif_cont_reg;
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * We must quiesce a dying CPU before it can be killed by the boot CPU. Because
+ * one or more cache may be disabled, we must flush to ensure coherency. We
+ * cannot use traditionl completion structures or spinlocks as they rely on
+ * coherency.
+ */
+static DEFINE_PER_CPU_ALIGNED(int, per_cpu_sw_state);
+
+static int per_cpu_sw_state_rd(u32 cpu)
+{
+ sync_cache_r(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
+ return per_cpu(per_cpu_sw_state, cpu);
+}
+
+static void per_cpu_sw_state_wr(u32 cpu, int val)
+{
+ dmb();
+ per_cpu(per_cpu_sw_state, cpu) = val;
+ sync_cache_w(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
+}
+#else
+static inline void per_cpu_sw_state_wr(u32 cpu, int val) { }
+#endif
+
+static void __iomem *pwr_ctrl_get_base(u32 cpu)
+{
+ void __iomem *base = cpubiuctrl_block + cpu0_pwr_zone_ctrl_reg;
+ base += (cpu_logical_map(cpu) * 4);
+ return base;
+}
+
+static u32 pwr_ctrl_rd(u32 cpu)
+{
+ void __iomem *base = pwr_ctrl_get_base(cpu);
+ return readl_relaxed(base);
+}
+
+static void pwr_ctrl_set(unsigned int cpu, u32 val, u32 mask)
+{
+ void __iomem *base = pwr_ctrl_get_base(cpu);
+ writel((readl(base) & mask) | val, base);
+}
+
+static void pwr_ctrl_clr(unsigned int cpu, u32 val, u32 mask)
+{
+ void __iomem *base = pwr_ctrl_get_base(cpu);
+ writel((readl(base) & mask) & ~val, base);
+}
+
+#define POLL_TMOUT_MS 500
+static int pwr_ctrl_wait_tmout(unsigned int cpu, u32 set, u32 mask)
+{
+ const unsigned long timeo = jiffies + msecs_to_jiffies(POLL_TMOUT_MS);
+ u32 tmp;
+
+ do {
+ tmp = pwr_ctrl_rd(cpu) & mask;
+ if (!set == !tmp)
+ return 0;
+ } while (time_before(jiffies, timeo));
+
+ tmp = pwr_ctrl_rd(cpu) & mask;
+ if (!set == !tmp)
+ return 0;
+
+ return -ETIMEDOUT;
+}
+
+static void cpu_rst_cfg_set(u32 cpu, int set)
+{
+ u32 val;
+ val = readl_relaxed(cpubiuctrl_block + cpu_rst_cfg_reg);
+ if (set)
+ val |= BIT(cpu_logical_map(cpu));
+ else
+ val &= ~BIT(cpu_logical_map(cpu));
+ writel_relaxed(val, cpubiuctrl_block + cpu_rst_cfg_reg);
+}
+
+static void cpu_set_boot_addr(u32 cpu, unsigned long boot_addr)
+{
+ const int reg_ofs = cpu_logical_map(cpu) * 8;
+ writel_relaxed(0, hif_cont_block + hif_cont_reg + reg_ofs);
+ writel_relaxed(boot_addr, hif_cont_block + hif_cont_reg + 4 + reg_ofs);
+}
+
+static void brcmstb_cpu_boot(u32 cpu)
+{
+ /* Mark this CPU as "up" */
+ per_cpu_sw_state_wr(cpu, 1);
+
+ /*
+ * Set the reset vector to point to the secondary_startup
+ * routine
+ */
+ cpu_set_boot_addr(cpu, virt_to_phys(brcmstb_secondary_startup));
+
+ /* Unhalt the cpu */
+ cpu_rst_cfg_set(cpu, 0);
+}
+
+static void brcmstb_cpu_power_on(u32 cpu)
+{
+ /*
+ * The secondary cores power was cut, so we must go through
+ * power-on initialization.
+ */
+ pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, 0xffffff00);
+ pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1);
+ pwr_ctrl_set(cpu, ZONE_RESERVED_1_MASK, -1);
+
+ pwr_ctrl_set(cpu, ZONE_MAN_MEM_PWR_MASK, -1);
+
+ if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_MEM_PWR_STATE_MASK))
+ panic("ZONE_MEM_PWR_STATE_MASK set timeout");
+
+ pwr_ctrl_set(cpu, ZONE_MAN_CLKEN_MASK, -1);
+
+ if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_DPG_PWR_STATE_MASK))
+ panic("ZONE_DPG_PWR_STATE_MASK set timeout");
+
+ pwr_ctrl_clr(cpu, ZONE_MAN_ISO_CNTL_MASK, -1);
+ pwr_ctrl_set(cpu, ZONE_MAN_RESET_CNTL_MASK, -1);
+}
+
+static int brcmstb_cpu_get_power_state(u32 cpu)
+{
+ int tmp = pwr_ctrl_rd(cpu);
+ return (tmp & ZONE_RESET_STATE_MASK) ? 0 : 1;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void brcmstb_cpu_die(u32 cpu)
+{
+ v7_exit_coherency_flush(all);
+
+ per_cpu_sw_state_wr(cpu, 0);
+
+ /* Sit and wait to die */
+ wfi();
+
+ /* We should never get here... */
+ while (1)
+ ;
+}
+
+static int brcmstb_cpu_kill(u32 cpu)
+{
+ /*
+ * Ordinarily, the hardware forbids power-down of CPU0 (which is good
+ * because it is the boot CPU), but this is not true when using BPCM
+ * manual mode. Consequently, we must avoid turning off CPU0 here to
+ * ensure that TI2C master reset will work.
+ */
+ if (cpu == 0) {
+ pr_warn("SMP: refusing to power off CPU0\n");
+ return 1;
+ }
+
+ while (per_cpu_sw_state_rd(cpu))
+ ;
+
+ pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1);
+ pwr_ctrl_clr(cpu, ZONE_MAN_RESET_CNTL_MASK, -1);
+ pwr_ctrl_clr(cpu, ZONE_MAN_CLKEN_MASK, -1);
+ pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, -1);
+ pwr_ctrl_clr(cpu, ZONE_MAN_MEM_PWR_MASK, -1);
+
+ if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_MEM_PWR_STATE_MASK))
+ panic("ZONE_MEM_PWR_STATE_MASK clear timeout");
+
+ pwr_ctrl_clr(cpu, ZONE_RESERVED_1_MASK, -1);
+
+ if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_DPG_PWR_STATE_MASK))
+ panic("ZONE_DPG_PWR_STATE_MASK clear timeout");
+
+ /* Flush pipeline before resetting CPU */
+ mb();
+
+ /* Assert reset on the CPU */
+ cpu_rst_cfg_set(cpu, 1);
+
+ return 1;
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static int __init setup_hifcpubiuctrl_regs(struct device_node *np)
+{
+ int rc = 0;
+ char *name;
+ struct device_node *syscon_np = NULL;
+
+ name = "syscon-cpu";
+
+ syscon_np = of_parse_phandle(np, name, 0);
+ if (!syscon_np) {
+ pr_err("can't find phandle %s\n", name);
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ cpubiuctrl_block = of_iomap(syscon_np, 0);
+ if (!cpubiuctrl_block) {
+ pr_err("iomap failed for cpubiuctrl_block\n");
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ rc = of_property_read_u32_index(np, name, CPU0_PWR_ZONE_CTRL_REG,
+ &cpu0_pwr_zone_ctrl_reg);
+ if (rc) {
+ pr_err("failed to read 1st entry from %s property (%d)\n", name,
+ rc);
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ rc = of_property_read_u32_index(np, name, CPU_RESET_CONFIG_REG,
+ &cpu_rst_cfg_reg);
+ if (rc) {
+ pr_err("failed to read 2nd entry from %s property (%d)\n", name,
+ rc);
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+cleanup:
+ of_node_put(syscon_np);
+ return rc;
+}
+
+static int __init setup_hifcont_regs(struct device_node *np)
+{
+ int rc = 0;
+ char *name;
+ struct device_node *syscon_np = NULL;
+
+ name = "syscon-cont";
+
+ syscon_np = of_parse_phandle(np, name, 0);
+ if (!syscon_np) {
+ pr_err("can't find phandle %s\n", name);
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ hif_cont_block = of_iomap(syscon_np, 0);
+ if (!hif_cont_block) {
+ pr_err("iomap failed for hif_cont_block\n");
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ /* Offset is at top of hif_cont_block */
+ hif_cont_reg = 0;
+
+cleanup:
+ of_node_put(syscon_np);
+ return rc;
+}
+
+static void __init brcmstb_cpu_ctrl_setup(unsigned int max_cpus)
+{
+ int rc;
+ struct device_node *np;
+ char *name;
+
+ name = "brcm,brcmstb-smpboot";
+ np = of_find_compatible_node(NULL, NULL, name);
+ if (!np) {
+ pr_err("can't find compatible node %s\n", name);
+ return;
+ }
+
+ rc = setup_hifcpubiuctrl_regs(np);
+ if (rc)
+ return;
+
+ rc = setup_hifcont_regs(np);
+ if (rc)
+ return;
+}
+
+static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ /* Missing the brcm,brcmstb-smpboot DT node? */
+ if (!cpubiuctrl_block || !hif_cont_block)
+ return -ENODEV;
+
+ /* Bring up power to the core if necessary */
+ if (brcmstb_cpu_get_power_state(cpu) == 0)
+ brcmstb_cpu_power_on(cpu);
+
+ brcmstb_cpu_boot(cpu);
+
+ return 0;
+}
+
+static struct smp_operations brcmstb_smp_ops __initdata = {
+ .smp_prepare_cpus = brcmstb_cpu_ctrl_setup,
+ .smp_boot_secondary = brcmstb_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_kill = brcmstb_cpu_kill,
+ .cpu_die = brcmstb_cpu_die,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(brcmstb_smp, "brcm,brahma-b15", &brcmstb_smp_ops);
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